1. Field of the Invention
The present invention relates to a plate-like specimen fluid-treating apparatus and a plate-like specimen fluid-treating method. More particularly, the invention relates to a plate-like specimen fluid-treating apparatus and a method therefore, wherein a plate-like specimen (e.g., a wafer such as a semiconductor wafer) is arranged between parallel upper and lower Bernoulli-plates and disposed in a parallel confronting relation to inner surfaces of the upper and lower Bernoulli-plates, the plate-like specimen being subjected to a fluid treatment (e.g., cleaning) by ejection of a treatment liquid (e.g., a cleaning liquid) onto opposite surfaces of the plate-like specimen which is driven to rotate.
2. Description of the Related Art
A conventional sheet cleaning apparatus, known as a fluid treatment apparatus adapted for a plate-like specimen, is designed as shown in FIG. 5, wherein a cleaning liquid is ejected to a wafer 100 from a plurality of jet nozzles 104 under an atmosphere while the wafer 100 is being chucked with a chuck pin 102, thereby cleaning the wafer. In this structure, the cleaning liquid is ejected in a neighborhood of a central portion of the wafer which is driven to rotate, thus causing the cleaning liquid on the wafer to be blown to an outer periphery of the wafer by mean of centrifugal force for cleaning thereof. The cleaning liquid is used at a chemicals temperature of about 80xc2x0 C. in dependence of cleaning purposes.
However, since the wafer 100 onto which the cleaning liquid is ejected is normally at room temperature, it is needed to take into consideration a time for rising in temperature of the wafer. On the other hand, since the wafer will emit heat from a rear surface thereof while the wafer is being heated by the cleaning liquid, it requires a large amount of heat capacity, i.e., a great amount of the cleaning liquid, for rising in temperature of the wafer to about 80xc2x0 C. Furthermore, the temperature of the cleaning liquid as ejected above will be remarkably lowered as the cleaning liquid goes to the periphery of the wafer 100 farther from a location at which the cleaning liquid is put down on the surface of the wafer 100, thereby causing its temperature distribution on the wafer to be locally largely varied in temperature difference. As a result, the wafer 100 may be irregularly cleaned so that it will be difficult to shorten a cleaning time without an extra consumption of the cleaning liquid.
To meet such problems, there is proposed a cleaning treatment apparatus in Japanese laid-open patent publication No. 09-17761. In this prior art apparatus, a heating-medium circulating passage arrangement is disposed under a holding surface mounted on a spin chuck body and adapted for rotatably holding a wafer thereon. Above the spin chuck, there is provided a heat-insulation body having a cleaning-liquid supply nozzle and adapted to be movable upwardly and downwardly with respect to the spin chuck. The cleaning-liquid supply nozzle is capable of supplying a cleaning liquid to the wafer held on the holding surface of the spin chuck. The heat-insulation body defines in cooperation with the spin chuck a heat insulation space for the wafer and the cleaning liquid. The heating-medium circulating passage arrangement is configured to keep the wafer held on the holding surface and the cleaning liquid at predetermined temperatures by means of circulation of the heating medium for temperature adjustment. Thus, it has been realized to reduce variations of a supply amount of the cleaning liquid and the time for cleaning treatment, thereby improving a throughput.
Disadvantageously, this prior art apparatus will inevitably interpose a large spacing or gap between the wafer and the heat insulation body, as a result of which it will be necessary to supply a great amount of the cleaning liquid for heating the wafer. Also, the wafer is directly placed on the holding surface of the spin chuck in this apparatus. Therefore, if the wafer has already been warped as a result of its thermal insulation previously continued or by the other treatments, there will be occurred temperature differences between uncontacted locations of the wafer due to its warp and contacted locations of the wafer with the holding surface of the chuck. This may disadvantageously lead to a cleaning irregularity of the wafer.
In view of the above, an object of the present invention is to provide a plate-like specimen fluid-treating apparatus and a method therefor by which it is enabled to uniform the temperature distribution of wafer along with shortening or saving of time for a treatment (cleaning) task, reduction of a treatment (cleaning) liquid, and prevention of occurrence of treatment (cleaning) irregularity. Consequently, it is possible to improve a yielding, a throughput and a cost reduction.
To this end, the present invention has a plate-like specimen fluid-treating apparatus including upper and lower Bernoulli-plates disposed in parallel with each other, wherein a plate-like specimen is disposed between the upper and lower Bernoulli-plates in a parallel confronting relation to inner surfaces of the upper and lower Bernoulli-plates such that a narrow gap of about 0.2 to 2 mm is created between the plate-like specimen and at least the upper Bernoulli-plate, and wherein at least the upper Bernoulli-plate and the plate-like specimen are relatively rotated while a treatment liquid is ejected to at least an upper surface of the plate-like specimen to treat the plate-like specimen, and a passage provided on the upper and lower Bernoulli-plates and adapted for supplying the upper and lower Bernoulli-plates with a heating medium or a cooling medium to heat or cool the upper and lower Bernoulli-plates.
Since at least the upper Bernoulli-plate and the plate-like specimen are spaced from each other to define the narrow gap therebetwen, it is possible to interpose only a cleaning liquid between the plate-like specimen and the upper Bernoulli-plate. Then, upon cleaning the rotating wafer, this clearance between the plate-like specimen and the upper Bernoulli-plate are allowed to be in a vacuum state. Therefore, it is possible to accurately and rapidly elevate the temperature of the plate-like specimen by a small amount of the cleaning liquid .
Also, in the present invention, the plate-like specimen preferably is disposed between the upper and lower Bernoulli-plates in such a manner that one surface of the plate-like specimen is spaced with a narrow gap from the upper Bernoulli-plate and that the other surface of the plate-like specimen is spaced with a narrow gap from the lower Bernoulli-plate.
Thus, since the plate-like specimen is heated in non-contact with the upper and lower Bernoulli-plates according to the present invention, any temperature differences cannot be occurred partially over the plate-like specimen, thereby heating the overall plate-like specimen uniformly.
Further, in the present invention, the plate-like specimen preferably is disposed between the upper and lower Bernoulli-plates in such a manner that one surface of the plate-like specimen is spaced from the upper Bernoulli-plate by a gap by which the other surface of the plate-like specimen is equivalently spaced from the lower Bernoulli-plate.
Thus, since the gap or clearance formed between the plate-like specimen and the upper Bernoulli-plate can be equal to that formed between the plate-like specimen and the lower Bernoulli-plate, it is easily possible to equally and uniformly elevate both temperatures of the cleaning liquid supplied to an upper side of the plate-like specimen and of the cleaning liquid supplied to a lower surface of the plate-like specimen.
According to another aspect of the present invention, a plate-like specimen fluid-treating method includes disposing upper and lower Bernoulli-plates in parallel with each other to define a narrow gap therebetween, disposing a plate-like specimen between the upper and lower Bernoulli-plates in a parallel confronting relation to inner surfaces of the upper and lower Bernoulli-plates such that the plate-like specimen is spaced with a narrow gap of about 0.2 to 2 mm from at least the upper Bernoulli-plate, and wherein at least the upper Bernoulli-plate and the plate-like specimen are relatively rotated while a treatment liquid is ejected to at least an upper surface of the plate-like specimen to treat the plate-like specimen, and supplying the upper and lower Bernoulli-plates with a heating medium or a cooling medium to heat or cool the treatment liquid to a predetermined temperature.
Thus, since the plate-like specimen can be treated by using the treatment liquid heated or cooled at the predetermined temperature, it is possible to enhance a treatment efficiency.
Also, the method of the present invention preferably further includes preparing a plurality of kinds of treatment liquids, and upon ejecting the treatment liquids to at least an upper surface of the plate-like specimen, heating or cooling the treatment liquids to temperatures dependent on their service purposes by using the heating medium or cooling medium.
When several kinds of treatment liquids are used, temperatures at which such different treatment liquids are used have to differ from each other in dependence of their intended purposes. According to the present invention, it is possible to rapidly elevate temperatures of the treatment liquids dependent on their intended purposes as well as temperatures of the Bernoulli-plates and the plate-like specimen. Therefore, it is advantageously enabled to save the time for treatment and cost in comparison with a treatment (cleaning) apparatus dedicated for only one kind of treatment liquid having its intended service temperature.